and the one guy who stayed with the bike shot himself? Or maybe the the others overpowered him and shot him?

It sounds very strange because I don't think Pal Anders would just leave his bike like that?

It sounds like a classic scam: at first they appear to help him, one stays with the victim (Pal), the others with the valuables (bike). Then something unforseeable happens allegedly "my brother shot himself! I must go!" and the victim remains alone.

Hard to say if that's how it went down, but that's what it sounds like to me.